Own Dell Optiplex desktop GX 280 ( bios A04 (02/09/05). Bios has administrator password which I don't know. Tried using backdoor password, third party software for revealing password, no luck. Disconnected CMOS battery which changed date and time but did not remove the administration password locked BIOS. Could not find BIOS clearing junpers on motherboard which I don't know if that could solve the problem, which is to be able to change the boot order so I can reinstall windows xp. Any help will be appreciated from this forum since I have run out of options short of replacing the motherboard or the computer itself.